Stereoscopic range and height finder with adjustable reticles



8- 7- L. M. APPLEGATE 2,425,713

STEREOSCOPIC RANGE AND HEIGHT FINDER WITH ADJUSTABLE RETICLES Filed July30, 1943 Lindaqy M-A 1egn ca $2, a. a/Mum M machine known as a director.

, Patented Aug. 19, 1947 PATENT OFFICE STEREOSCOPIC RANGE AND HEIGHTFINDER wrrn ADJUSTABLE BETICLES Lindsay M. Applegate, Portland, Oreg.

Application July 30, 1943, Serial No. 496,700

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3700. G. 757) 6 Claims.

' relayed or transmitted, together with other infomation such as presentazimuth and present angular height, target velocity, etc., to acomputing The target data, including the range as determined by thestereoscopic range finder, is entered into the director, together withsuch known data as muzzle velocity of the gun. From these given data thedirector automatically determines the set forward position or futureposition of the target (1. e., the position at which the targettraveling at the determined velocity will be hit by the projectile firedfrom the gun of known ballistic characteristics) from this automaticdetermination of the set-forward position, the director yields theinformation required to properly train the gun to cause its projectileto hit the target at the said future position, this information beingprincipally lateral lead, superelevation, and fuse time setting.

The object of this invention is to provide a fire control apparatuswhich is combined with the stereoscopic range finder, and which isimplemented with means for establishing the set-forward or futureposition of the target within the stereoscopic or three-dimensional viewof the improved fire-control range finder. That is the observer not onlymanipulates the stereoscopic device to make stereoscopic contact betweenthe target-image and the reticle of the device, in the usual manner, butalso, by means fully described herein, shifts the reticle ahead of thetargetimage to bring the reticle to the future or predicted position ofthe target. For this purpose the reticle is not fixedf On the contrary,the reticle .of the improved fire-control device is capable of beingmoved so that its image within the three-dimensional view may be made tomove in three spatial directions. The device is provided with certainmanual knobs, fully described subsequently, for so shifting thereticle-image spatially to the set-forward or predicted position of thetarget-image, The manipulation of the manual knobs in shifting thereticle-image to the future target position, also function to operatecomputing mechanism similar to the computing instrumentalities of thedirector (briefly described above) to yield the same information as thatgotten from the director, namely, lead, superelevation etc.

For the attainment of the foregoing and such other objects as may appearor be pointed out herein I have shown one embodiment of my invention inthe accompanying drawing, wherein:

Fig. 1 is a schematic plan view of the optic train of the improved firecontrol device of this invention.

Fig. 2 is an isometric view of the aforementioned manual knobs forcontrolling the spatial shifting of the reticle-image to the predictedtarget position.

Before describing the improved fire control means of this invention, theconventional stereoscopic range finder will be first briefly outlined.Referring to Fig. 1, rays I and II emanating from the target enter theinstrument, with rays l (which schematically represent the binocularView of the target as seen from the left side) entering the instrumentat the left, at end reflecting surface 2; rays l I, which schematicallyrepresent the binocular view of the target as seen from the right side,enter the instrument at the right, at end refleeting surface l2. Theleft rays I and right rays l l, upon reflection from their respectiveend reflectors 2 and i2, are again reflected, at 3 and I3, and directedaxially inwardly to central prisms, respectively, left prism I and rightprism [1. Between the end reflectors, 3 and I3, and the central prisms,1 and H, the left and right rays successively pass through objectivelenses, respectively, 4 and I4, collective lenses, 5 and I5, anderecting lenses, 6 and IS. Following a shift at the central prisms, 1and 11, the left and right rays are directed through collective lenses,respectively, 8 and. I8, and eye lenses, 9 and I9.

The left eye of the observer is placed before left eye lens 9, with hisright eye before right eye lens l9, so that the left eye can see onlythe rays I representing the binocular view of the target as seen fromthe left, and. so that the right eye can see only the rays llrepresenting the binocular view of the target as seen from the right.Both left and-right rays are fused'in the brain of the observer so thatwhat is actually seen is a three-dimensional or solid view of the objector target. The conventional range finder is implemented with means forshifting the distance plane of the target as viewed in the instrument,so that the distance plane will appear to be nearer to, or further awayfrom, the observer. This shifting of the distance plane is achievedbychanging the lateral distance between corresponding points in the'twopictures viewed; for this purpose there is provided in either the leftray or the right ray path-in the right ray path, as shown in Fig. lapair of complementary measuring wedges lfl. These are a pair ofoppositely or complementarily beveled pieces of optic glass, which arerotatively adjustable to cause the image-the right image, as shown inFig. lto be shifted laterally. Thus by laterally image can-be--varied tocause ashifting of the distance plane (as explained above).

One type of known range finder is provided with hair-line guide marks orreticles which areusually associated with the collective lenses -5--That is, identical reticletmarks i and I5, Fig. 1.

are provided on both the left collective lensi5 A and the rightcollective lens l5, so that the 010-" server sees a single fused reticlein the three-- dimensional view, which serves-as -a reference point indetermining the range: of: the-target;-

What an observer sees when looking through a stereoscopic trangefinderis a fusedorv three-dimensional image of, the target. ,andflof thepetiole.-

By rotating the measuring wedges j 0. the target i e and the reticleimage are .made to be i in.

the same distance .plane, at whichacoincidence stereoscopic ,c ontactfis said to be estab1ished...

By associating the measuring wedges with a cali,,-.. brated scale, anobserver, blestablishing-stereo.-

scopic contact with a target, can byjconsultingscale determine th'erangetosthe e \ca ra d 7 target. H t, V

In the aforesaid known stereoscopic range finder the reticles,left,'5,-and right,15,7are fixed. .In

the fire control device of, this inventiomon .Ithe other ;hand, the left:and, right reticlesl may be t adjusted; in, v arious ways which willnow be de. scribed; Whereas in the ,Opel'ation .of'the stereo;-

scopic rangefinder stereoscopic contact'is esta b-.

lishedby bringingthetarget imageand th'e r.e ticlej-i mage'into,;coincidence,yin the fire control d evice of this invention, the,reticles, 5 and I5, are adjusted, as well as-the measuring wedges H],which control the,distance plane of the target image; so as ,to,'advance the. reticle image ahead of the present'target positionto thefuture or predicted set-forward position of the target.

Prediction is accomplished by what in effect is. visually estimating -inthe; stereoscopic or threedimensional view; the futureposition ',of thetar-s get, byadvancing the reticle- (i; -e., thefused image-therefromas; seen inthe three-dimensional view) to tha-t position. It should henoted that the reticle is-shifted1oradvanced in three directions,namely; horizontal-1y or vertically laterally in a g-ivendistanceplaneor in a" direction nor-'- mal to the saidlateralmovementsy-ornormal; to the distance-planes,- the latter movementbee. ing ineffectfrom onejdistanceplane-to another.

For-convenience the said first two-directions will be refer-reciteas;horizontal-lateral and vertical-latera-l;- and the said thirddirection will be.

referredto as distance-plane.

The following mechanism; shown in Fig. 2,

maybe employed foradjusting the left reticle '25 and the-right;reticle35, sopthat the fused' image ofthe-reticle mambeshifted inthe said threedirectionswLeft reticle 25 is secured at "the" 1 left endof-a rod 24 which' is telescopically r'ee.

ceived in=a -tubular rodor-slide 34-at-the right endof==whichis-secured'the-right reticle 35. As

explainedabove in -connection with the; convenbracket-'36 is securedtothe tubular rod orslide 34, as bya. set screw -or the like-31. Bracket36 provides bearings for amanipulative rod 31 at one endof which isaknob- 311 and at-theother end of which is a gear 32 which clears througha slot 33. provided in the tubular-- rod 34, to mesh with rack'teethprovidedalong the right end portion of inner rod 24.

..Th'e tubular rod .34 is supported for an extent i oflongitudinalimovement in a left bearing member 45'and a right bearingmember 45' which are integrally united-by a horizontal brace bar 44.Orr-brace bar 44 is provided an upstanding hearing 43 for a manipulativerod 4|. At one end of manipulative rod 4| is a knob 40 and at the otherendqis secured=augear 42 which meshes with a rack 38 secured to theunderside of the tubular rod 34. Rotations of knob 40 is effective tomove the tubu1ar-rod- 34to the left and right, thus moving together oras a unit, the right ret icle; 35,- -Which is secured atthe right end oftubular rod 34, and the left reticle 25 whichis' secured :at the-leftend of inner rod 24 which is carriedby-the outer tubular-rod'34;--'I-hus rota tion of knob 40- is elfective toimpart horizonta1- lateralmovements .to the reticles- 2535; andtotheir fused image asseen in-the-stereoscopic VieWpH. .z. v i

Left bearing member 45 is mounted for an extent= of .vertical slidingmovement ina--lefttrackway 6.5 provided at the leftofa-frame plate 6|..At.the. "right ..of..frame iplate 6li is -aright trackway 65 inlwhichslides the right-bearing member 45 of the unit 454445, for. an extentof'vertical'movement. The left bearing member- 45 is provided with arack 46 while arack 46' is provided on the right bear-ing member 45'.

Meshing with the. two vertically-disposed racks 46 and 46 are gears,respectively, "55' and 56 which are secured on a horizontal shaft154which is mounted on end bearings64 left end 64", right, provided: on theframe pIate-GI-QmOre particularly, projecting laterally from. the'saidend slidetracks, respectively, 65 and '65. Al'sosecuredhn horizontal rod54 is'a bevel "gear '53 whichmeshes with-a bevel gear '52 which. is"secured at one end of a manipulative rod 5|." The frame plate 6! isprovided with an angle bracket "62 which serves as bearings "for themanipulative "rod 5| and the horizontal shaft 54. At'the'oth'ei end ofmanipulative rod5l i's'aknob-5'0.- Rotation of knob -50 'is' effectiveto rotate horizontal shaft '54 andits gears 56"and 56' and'thereby toelevate the frame -454445' 'an'd" thusthe *telesc'opi'c rods-24' and 34;which are'm'ounted inthe bear ing members 45 211161 45) as describedabove. Thus the knob 5fl is effective to 'move'the' reticles 25,

35, in the-said vertical-lateral direction." To recapitulate,manipulative knob "30 is adjusted to shift the reticle'inthe saiddistanceplane direction; manipulative-knob 4B is adjust-" ed to shiftthe reticle'in' the said horizontal-lat eraldirection manipulative knob"50 is 4 adjusted" to shift the reticle in thesaidwertical lateral directionf By operating the knobs30, 4Uia'nd' 50" perelevation, and fusesetting.

Ic'laimt' 1. In a device for determining, from the present position ofa'moving target, theda'tarequired for training a gun of knowncharacteristics to cause projectiles therefrom to hit the said target ata predicted future position, the combination of a stereoscopic rangefinder having left and right eyepieces and left and right optic trainsincluding a left and a right collective lens adapted to form athree-dimensional image of a target and to shift the distance-planethereof, a left and a right reticle associated with the said collectivelenses and adapted to be formed as a threedimensional image of thereticle, means for altering the distance between the left and the rightimage of the target to cause stereoscopic contact between thedistance-plane of the target and the distance-plane of the reticle byrelative movement thereof in the distance-plane direction, means foraltering the distance between the said pair of reticles to advance thedistance-plane of the reticle image ahead of its said present position,in the said distance-plane direction, to the said predicted futureposition, and means for moving the said pair of reticles in unison,maintaining their said distance apart, to shift the lateral position ofthe said reticle image of the said predicted future position of thetarget both vertically and horizontally in the said adjusted distanceplane of the reticle image.

I 2. In a device for determining, from the present position of a movingtarget, the data required for training a gun of known characteristics tocause projectiles therefrom to hit the said target at a predicted futureposition, the combination of a. stereoscopic range finder having leftand right eyepieces and left and right optic trains adapted to form athree-dimensional image of a target and to shift the distance-planethereof, a left and a right reticle associated with the said optictrains and adapted to be formed as a three-dimensional image of thereticle, means for altering the distance between the left and the rightimage of the target to cause stereoscopic contact between thedistance-plane of the target and the distanceplane of the reticle byrelative movement thereof in the distance-plane direction, means foraltering the distance between the said pair of reticles to advance thedistance-plane of the reticle image ahead of its said present position,in the said distance-plane direction, to the said predicted futureposition, and means for moving the said pair of reticles in unison,maintaining their said distance apart, to shift the lateral position ofthe said reticle image of the said predicted future position of thetarget both vertically and horizontally in the said adjusted distanceplane of the reticle image.

3. In a device for determining, from the present position of a movingtarget, the data required for training a gun of known characteristics tocause projectiles therefrom to hit the said target at a predicted futureposition, the combination of a stereoscopic range finder having left andright eyepieces and left and right optic trains adapted to form athree-dimensional imag of a target and to shift the distance-planethereof, a pair comprising left and a right reticles associated with thesaid optic train and adapted to be formed as a three-dimensional imageof the reticle, means for altering the distance between the said pair ofreticles to advance their distanceplane to an estimated predicted futureposition, and means for moving the said pair of reticles in unison,maintaining their said distance apart, to shift the lateral position ofthe said reticle image of the said predicted future position of thetarget both vertically and horizontally in the distance plane of thereticle image.

4. A stereoscopic range finder of the type having right and left groupsof optical elements arranged along an axis and adapted to provide astereoscopic image of a distant object when viewed through right andleft eyepieces cooperating with said groups respectively, comprising aframe, a bearing member guided for translation by said frame in a firstdirection normal to said axis, a first slide carried by said bearingmember for translation in a second direction parallel to said axis, asecond slide carried by said first slide for translation in said seconddirection, means connecting said slides for equal and opposite movementrelatively to said bearing member, and a reticle carried by each saidslide, each reticle being interposed in a respective group of elementsand on said axis.

5. A stereoscopic range finder having right and left groups of opticalelements arranged along an optical axis and right and left eyepiecesinto which said groups are adapted to project an image of a target whenviewed through said eyepieces, a pair of reticles each interposed in arespective group of said elements along said axis, first meansconnecting said reticles for equal and opposite translation along saidaxis, second means mounting said first means for translation wherebysaid reticles may be moved as a unit along said axis, and third meansmounting said first and second means for translation to effect movementof said reticles as a unit transversely of said axis.

6. A stereoscopic range finder having groups of optical elements adaptedto project images of a target along a common axis into right and lefteyepieces for fusion in a first distance plane by an observer lookinginto said eyepieces, comprising a pair of reticles each interposed in 9,respective group of optical elements along said axis for fusion by saidobserver in a second distance plane, first means mounting said reticlesfor conjoint movement in and along said axis to vary the apparentseparation of said planes, and second means mounting said first means tomove said reticles transversely of said axis whereby operation of saidtwo means effects apparent movement of said reticle in three dimensionsrelatively to the image of said target, as viewed through saideyepieces.

LINDSAY M. APPLEGATE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

